The present invention relates to a device and method for determining the moisture content of tobacco, particularly tobacco in the form of bales.
Many different types of synthetic and organic materials are the basis for the construction of many different manufactured products. These materials must be gathered, transported and stored before being used in the manufacturing process. The manufacturing process itself may require multiple procedures, first to prepare the raw material, and then to use the processed material in the formation of the actual product. Many of these procedures are dependent upon the moisture content of the material. If the moisture content is too high, for example, the material may decompose during storage and transportation, before it can be used. If the moisture content is too low, processing and use of the material may be difficult.
Synthetic and organic materials whose behavior depends upon their moisture content include cotton, paper, wool, seeds, tobacco, pharmaceuticals and synthetic fibers. As an example, tobacco can be considered, although it will be appreciated that similar examples could be given for any of the above materials.
Tobacco is typically stored in large bales before being processed to manufacture cigarettes, pouch tobacco, chewing tobacco and other tobacco products. As it is stored, the chemical composition of the tobacco material can alter as a result of various reactions involving compounds found in tobacco. Some of these reactions can produce chemical products which are particularly harmful to people who smoke, while other products are detrimental to the taste and shelf life of the tobacco. Indeed, the relevant regulatory authority in each country, such as the FDA (Food and Drug Administration) for the United States of America, frequently request maximum levels of the harmful chemical compounds. If the concentration of one or more of these components exceeds this limit, the regulatory authority may not permit the tobacco to be sold within the country. The rate and extent of these reactions may be altered by the moisture content of the tobacco. Therefore, the tobacco industry must process the tobacco within a relatively narrow range of moisture values, in order to comply with these regulations and in order to maintain the quality of the tobacco. Thus, clearly the concentration of these components within the tobacco must be monitored, and if possible the tobacco must be processed substantially before such components increase to potentially harmful levels.
The rate and extent of such reactions is often influenced by the moisture content of the tobacco. Therefore, in order to optimally store and process the tobacco, measurements of the moisture content of the tobacco may be performed. Unfortunately, currently available methods for the measurement of the moisture content of the tobacco involve the removal of samples from the tobacco bale, and the determination of the moisture content of the samples alone. Such sampling can be very inaccurate, since the moisture content of the tobacco may vary widely throughout the bale, thereby yielding misleading results. In addition, measurement of the moisture content of the loose tobacco leaves is also important, yet is also difficult to determine by sampling small portions of material. Preferably, such bulk volumes of material would be measured as the leaves pass through a silo, for example on a conveyor belt, rather than by sampling the material. Thus, currently available methods for measuring the moisture content of both tobacco bales and bulk volumes of loose leaves have significant drawbacks.
A far more useful method for determining the moisture content of tobacco would involve the measurement of the moisture content throughout the bale, such that a more accurate moisture measurement could be made. Such a method would also preferably preserve the tobacco material, such that the tobacco would not be destroyed during the process of measuring the moisture content. Furthermore, the regulation of the moisture content can in turn control the level of the various chemical compounds which are produced as a result of the previously described chemical processes. Thus, an accurate determination of the moisture content of the tobacco is necessary for proper storage and manufacture of tobacco products.
There is thus widely recognized need for, and it would be highly advantageous to have, a method for measuring the moisture content of tobacco, which would enable the moisture content to be determined throughout the structure, such as the bale, substantially without destroying the tobacco material.